var banner = new Array();
       
       banner.push('https://i.servimg.com/u/f46/11/36/55/25/ban210.jpg');
        banner.push('https://i.servimg.com/u/f46/11/36/55/25/ban310.jpg');
        banner.push('https://i.servimg.com/u/f46/11/36/55/25/ban110.jpg');
       
       document.getElementById('i_logo').src= banner[Math.floor(Math.random()*banner.length)];